Superregenerative receiver



' SUPERREGENERAT IVE RECE I VER Filed Jan. 12, 1932 INVENTOR RU DOLF URTEL BY www ArroRNl-:Y

Patented oct. 24, 1933 y,

UNITED STATES ,PATENTV- QFFICE y j 1,931,950l

SUPERREGENERATIVE RECEIVER Rudolf Urtel, Berlin, Germany, assigner to Telefunken Gesellschaft fur Drahtlose. Telegraphic m. b. H., Berlin, Germany, a corporation'of Germany Application January'lZr, 1932, Serial No. 586,132, and in Germany June 23, 1931 4 Claims. (Cl'. Z50- 20),

The present invention relates to super-regenerative Vreceiver circuits and more specicallyto a new type of interruption energy kgenerating means. For the theory underlying in the opera- 5't'ion of a super-regenerativereceiver reference may be had to U. S. Patent No. 1,424,065 issued July 25, 1922 to E. H. Armstrong. It is evident from a study' of the above patent 'that in asuperregenerative receiver the coupling in a regeneratively connected electron discharge device is 1ncreased so that the tube or device is far beyond the oscillation point thus giving the circuit a negative resistance characteristic. The oscillations, however, are stopped periodically' by. suitable Imeans so that advantage of this negative resistance may be had for obtaining great amplication of the signals. The oscillations, so to speak, are stopped in the negative resistance circuit by introducing an effective resistance at denite intervals or by reducing the amount of regeneration. It is seen that by this means the circuit resistance becomes positive and negative alternately. In the priorV art, the variation in the circuit resistance is accomplished by varying the 25.-'Iplate voltage in some suitable manner preferably a vacuum tube oscillator employed to produce a periodic change in the amount of regeneration. Thepresent invention contemplates the use of a new type interrupting energy generator, which is removed from the regenerative receiver tube and preferably included in a separate circuit arrangement. The present invention also contemplates including the novel interrupting energy generator in the regenerative receiver tube circuit. More 35..'speci1'ically, the present invention utilizes for generating the interrupting energy a glow discharge or so-called gaseous conduction lamp.

This arrangement oiers the advantage that the setting of the super-regenerative tube is facili- 401tated, while compared with the scheme wherein the interrupting frequency energy is produced by a separate generator valve the advantage of a simpler arrangement is secured. Y A particularly advantageous simplification is obtained owing to the fact that in the interrupting energy circuit the receiver tube itself is directly used to act as the charging resistance for the glow-discharge tube arrangement.

The novel features which I believe to be char- Y ojiacteristic of my invention are set forth in particularity in the appended claims, the invention itself, however, as to both its organization and method of operation will best be understood by reference to the following description taken in 552iconnection with the drawing in which I have indicated diagrammatically several circuit organizations whereby my invention may be carried into effect. 1 Y Figure l illustrates diagrammatically a superregenerative receiver wherein the present inven- 6 tion is utilized to produce the interrupting frequency energy external to the regenerative tube; and, i

Figure 2 illustrates another form of the invention wherein the glow discharge tube for `producing the interrupting'frequency energyv is inserted in the .plate circuit of the. regenerative tube.

a In bothV figures; 1; denotesfthe .regenerative receiver tube for super-regenerative;reception70 2 the receiver circuit, 3 the tickler coil, and 4 the indicator connection. Referring specifically to Fig. 1, the glow-discharge lamp arrangement comprises the glow-discharge, or gaseous-conduction, lamp 5, the condenser 6 and the resistance 7, the arrangement being fed from the source 8. The potentials generated in the interrupting frequency energy circuit by way of the coupling 9 are induced, say, in the plate circuit of the regenerative tube 1 whereby they are made to control regeneration.

" 1 is as follows:

Tube 1 wherein the input and output circuits are coupled so as to produce a so-called negative resistance characteristic has impressed in the 954 output circuit thereof oscillations as generated by the circuit 5, 6, 7,8 through the tuned circuit 9. The frequency of the oscillations generated by the last-mentioned circuit is preferably high enough to be inaudible but, of course, not equal to the frequency of the desired incoming energy. The interrupting frequency generating circuit works as follows:

Condenser 6 is charged by means of the source connected across 8, 8 until the potential across its electrodesy becomes so high thatY a discharge takes place through the glow discharge tube 5. The effect of this discharge is to immediately lower the voltage across the electrodesA of condenser 6. It is evident therefore that, in effect,

an alternating current is transferred from the coil 7 to the tuned circuit 9 of the desired interrupting frequency. This alternating current alternately increases and decreases the plate voltage on tube 1 with the result that tube 1 has, in effect, iirst a negative resistance characteristic and then a positive resistance characteristie. The latter prevents the tube from bursting into oscillation. In Figure 2 substantially the same ideas are involved. The only difference being that the condenser is charged bythe rectifying action of the tube 1. In other Words, the direct current owing in the output of tube 1 charges the condenser 6. When the charge becomes great enough a discharge takes place through the discharge tube 5 thereby Varying the plate Voltage periodically.

While I have indicated and described several systems for carrying my invention intoeffect, it will be apparent to one skilled in the art that my invention is by no4 means limited to the pal',- ticularY organization shown and described, but that many modifications may be made without departing from the scope of my invention as set forthV in: the appended claims.

What is claimed is:

l. Apparatus for amplifying Varying electric currents comprising a feedback system having a certain degree of damping and means for periodically altering therelation between the amount of feedback and the degree of damping of the system forobtaining super-regenerative action, said means comprising a glow discharge tubeand charging condenser arrangement associated with a source of charging current.

2. Apparatus for amplifying Varying electric currents comprising a space discharge device having an input circuit and an output circuit, said input circuit being linked with the output circuit to facilitate the transfer of energy from the output circuit to the input circuit, said arrangement having a certain degree of damping and means for periodically altering the relation between the amount of feedback action and the degree of damping of said system for producing super-regenerative action therein, said last named means comprising a glow discharge tube andv means for periodically discharging through said tube.

3. A Vacuum tube regenerative system comprising a feedback circuit having damping and adjusted near thepoint of oscillation, a source of Varying potential current associated therewith comprising a glow discharge tube and charging condenser arrangement, and means by which saidy glow discharge tube causes a periodic Variation in both the amount of feedback and the damping of said rst circuit whereby super-regenerative action is obtained.

4. A vacuum tube regenerative system comprising an input circuit and an output circuit, said input and output circuits being linked so as to facilitate the transfer of energy from the output circuit to the input circuit, means for periodically varying the characteristics of said tube comprising a glow discharge tube and charging condenser arrangement in said output circuita utilizing circuity and means for coupling said output circuit thereto.

RUDOLF URTEL. 

